def _send_command(self, hex_bytes, expected_length):
    try:
        self.master.flushInput()  # Clear the input buffer
        self.master.write(hex_bytes)  # Send the command
        response = self.master.read(expected_length)  # Read the expected length of the response

        if response and response[-1:] == b'\x03':  # Check the last byte of the response
            return response
    except serial.SerialException as e:
        print(f"Serial communication error: {e}")
        time.sleep(1)  # Wait for a second before trying to reconnect
        self.reconnect()  # Attempt to reconnect

    return False

Key Points Explained

1. Clearing Input Buffer:

• self.master.flushInput(): Clears the input buffer before sending a new command to ensure no stale data is read.

1. Sending Command:

• self.master.write(hex_bytes): Sends the command in byte format to the device.

1. Reading Response:

• response = self.master.read(expected_length): Reads the response data of the expected length.

1. Response Check:

• Checks if the last byte of the response is b'\x03'. This can be adjusted based on your specific protocol.

1. Exception Handling:

• Catches serial.SerialException to handle communication errors.
• When an error occurs, it prints the error message, waits for one second, and then calls self.reconnect() to re-establish the connection.

Considerations

• Command Length: Ensure expected_length is appropriate to avoid reading beyond the device’s response length.
• Reconnecting: Make sure to handle the state after reconnecting (e.g., updating is_connected).
• Response Processing: You may need to further process the response content, such as parsing data or checking other protocol fields.

With these adjustments, your _send_command method will be more robust, effectively handling connection interruptions while maintaining communication continuity.